The Human Development Index (HDI)

An illustration of the difficulties faced when building economic indices

When
selecting the variables to include in a measure of human development,
controversy is inevitable as the decision-maker is essentially defining
what it is that gives people greater satisfaction and a better life

The
Human Development Index - bringing together income, health and education -
is used to compare human development in different nations

Key
changes to this indicator reflect the difficulty of such a statistical
exercise and of keeping the measure relevant. For instance, income is now
accounted for using the GNI rather than GDP, as the increasing flows of
international remittances skew national income figures and the index is
now composed using geometric, rather than arithmetic, mean to reflect the
fact that the different elements are not substitutable